1. Field of the Invention
This invention relates to the acquisition of data representing an airflow, with subsequent storage, transmission and/or playback of that data.
2. Related Art
The primary means of representing a human being (or other animate object, such as an animal) over time in media has been through audio, visual and audiovisual recordings, such as audiotape and video. For example, motion capture has been used to record movement of an animate object (e.g., human) in order to recreate the movement in a computer-generated character, often of the same form as the animate object for which movement was recorded (e.g., an animated human character). Motion capture evolved from the notion of rotoscoping. Rotoscoping is the mechanical tracing of images of an animate object from a series of film frames as the frames are projected onto a piece of paper or other drawing surface. Either the actual image is traced or the image is used as a guide to draw an imaginary animated character. Movement of an animated character is produced from the series of traced images, the movement mimicking the movement of the image in the series of film frames.
Motion capture is typically accomplished through either electromechanical or optical means. Electromechanical motion capture can be accomplished by fitting an animate object (typically a human being) with a wearable apparatus that has sensors at the joints, such as potentiometers or strain gauges. As the animate object moves, the sensors transmit signals to a computer that then decodes the signals into appropriate numerical representations for use in a computer model of the movement. This type of motion capture is awkward because of the encumbering nature of the wearable apparatus.
Optical motion capture is accomplished by visually recording the movement of an animate object (and, in particular, parts of the animate object) with one or more cameras, sometimes attaching visual markers to key positions (such as joints) on the animate object. The recorded image is analyzed to identify the positions of parts of the animate object (and/or visual markers) during the movement and joint angles at each point in time are computed. For recording human movement, optical motion capture gets rid of the encumbrance of the wearable apparatus used in electromechanical motion capture. However, optical motion capture suffers from difficulty in tracking the parts of the animate object (and/or marker positions) in the recorded image. Furthermore, if a single camera is used to record the motion, positions of parts of the animate object (and/or marker positions) are measured only in two-dimensions, in which case three-dimensional position information must be inferred, often incorrectly. While techniques exist for addressing these difficulties, no perfect techniques yet exist.
Physical aspects of, or effects produced by, a human being other than those that can be seen or heard (such as breath or wind flows arising from movement) are normally recorded or played back only for medical applications. Recording and playback of data representing such physical aspects can be both valuable from a historical perspective (e.g., the breath of a historic individual) and/or medical perspective, and interesting from an entertainment and/or communication perspective.
The “In Touch” system developed at Massachusetts Institute of Technology by Hiroshi Ishii et al. is a system for transmitting human movement to a remote location through a haptic device. The haptic device includes three rollers situated in a room. A person can move a part of the person's body (e.g., a hand) against the rollers. The haptic device is connected electronically to a second, identical haptic device located in a different room. The rollers of the second haptic device move in the same manner as the rollers of the first haptic device against which the person moves. A second person can push on the rollers of the second haptic device and thereby engage the first person, thus simulating pushing of the first person by the second person. Though the “In Touch” system enables transmission of the effects of human movement to a remote location, it does not record or amplify that movement. Additionally, the “In Touch” system transmits a human being's action on a simple mechanical system, rather than trying to represent a human movement directly.
Measured airflows (e.g., wind, breath) provide an underutilized source of sensory information. A large number of devices exist for measuring the velocity of an airflow. Many of these devices are typically referred to as anemometers and function in various ways, including hot-wire devices that sense the velocity of the airflow based on a change in temperature induced by the airflow and mechanical impellers that sense the velocity of the airflow based on the rotational speed of the impeller induced by the airflow. Additionally, some medical devices measure breath by using a diaphragm mounted around a patient's chest to measure the change in volume of the chest as the patient breathes, the chest volume changes corresponding to the patient's breathing volume. However, while airflows are sometimes measured—in particular, wind is often measured for meteorological applications—and there are many methods for doing so, data concerning airflows has only been viewed and analyzed in abstract terms as tables of numbers, graphs and/or graphical visualizations. Currently, no devices exist for playing back a measured airflow by producing a display airflow that corresponds to the measured airflow. Additionally, no devices exist for transmitting data representing a measured airflow to a location remote from that at which the measured airflow occurs.
Airflows can also be simulated. A large body of work exists on computationally modeling airflows, much of which provides complex models of airflow dynamics. However, as with measured airflows, simulated airflows have previously been viewed and analyzed in abstract terms as tables of numbers, graphs and/or graphical visualizations. Currently, other than conventional wind tunnels (which produce a display airflow that corresponds to a “simulated” airflow having a single specified velocity), no devices exist for playing back a simulated airflow by producing a display airflow that corresponds to the simulated airflow.